The present invention relates to a welding ring for connecting two housing parts of an electrical battery with electrode stacks arranged on both sides of a welding seam.
Relatively large pressure-tight electrical batteries, for example nickel/hydrogen cells, contain several electrode stacks connected electrically in series or in parallel. The housing for such batteries consists of a pressure-tight cylindrical casing which is composed of two housing halves connected by means of a radial joining weld. To prevent the electrode stacks from being damaged by the welding heat, the welding seam is arranged so that, as seen axially, it is located between two electrode stacks. Since the housing is joined together only after the electrode stacks have been constructed, welding beads must be reliably prevented from penetrating into the battery. Welding rings are conventionally used for this purpose. These rings cover from the inside the seam to be welded and thus prevent welding beads from penetrating into the housing. The welding rings also make it easier to center the two housing halves.
Such a welding ring is illustrated, for example, in U.S. Pat. No. 4,411,970. In this case, however, the battery contains only one electrode stack, and because of this the wall distance between the welding seam and the electrode stack is relatively great.
Furthermore, the welding ring according to U.S. Pat. No. 4,411,970 contains a nose which, when the ring is fitted, rests on the housing wall and prevents the ring from inadvertently slipping when the second housing half is pushed on.
In modern nickel/hydrogen cells, the cell housing is filled radially in an improved way. Because of the short radial distances between the electrode stack and the vessel wall, for thermal reasons, the housing can be welded only when the welding seam is located between two electrode stacks. However, where these larger housing containing several electrode stacks are concerned, there is the additional problem of holding the electrode stacks securely, so that contact between the electrode plates and the wall, which can result in short-circuits, is avoided.
An object of the present invention is to provide a welding ring which contributes to retention of the electrode stacks.
This object is achieved by providing a welding ring with spring tongues pointing radially inward and axially upward and downward. The spring tongues hold the electrode end plates of two opposing electrode stacks on their end faces against an appropriately shaped bearing point so as to center them and retain them axially. After the housing halves have been welded together, the welding ring is connected firmly to the container wall and the angled spring tongues fix the end plates of the electrode stacks as desired. To increase the bearing surface of the spring tongues on the electrode end plates, it is advantageous if the spring tongues are bent at their ends approximately perpendicularly relative to the axis of the ring. It is also advantageous if the free ends of the spring tongues are flanged so as to prevent the tongues (conventionally consisting of CrNi spring steel) from cutting sharply into the electrode end plates.
Further objects, features, and advantages of the present invention will become more apparent from the following description when taken with the accompanying drawings, which show for purposes of illustration only, an embodiment constructed in accordance with the present invention.